Height Estimation from Vector Fields of Surface Normals
نویسندگان
چکیده
In this paper we consider the problem of recovering the height information from a field of surface normals defined as three-dimensional (3-D) vectors. The algorithm starts from a certain location on the lattice and updates iteratively the heights in a neighbourhood. Then it proceeds to the neighbours of the already calculated heights. The updating rule is based on a gradient descent minimising the vector difference between the given surface normal, and the surface normal, extracted from the estimated height map at each site. The proposed algorithm is applied for recovering height information from Synthetic Aperture Radar (SAR) images of terrain.
منابع مشابه
On Depth Recovery from Gradient Vector Fields
Depth recovery from gradient vector fields is required when reconstructing a surface (in three-dimensional space) from its gradients. Such a reconstruction task results, for example, for techniques in computer vision aiming at calculating surface normals (such as shape from shading, photometric stereo, shape from texture, shape from contours and so on). Surprisingly, discrete integration has no...
متن کاملRobust Morse Decompositions of Piecewise Constant Vector Fields Supplementary Material
! Fig. 1. The Morse set containing a large periodic orbit in the diesel engine dataset (7 refinement steps). Fig. 2. Results for a height field on the original 1536-triangle mesh (left) and its subdivided version (three subdivision iterations). Note that only a source and two saddles are visible from this viewpoint. Fig. 3. Morse sets and connecting regions for the figure eight model subdivided...
متن کاملSurface acquisition from single gray-scale images
In this paper we show how a system for performing automatic surface model acquisition from single object views can be designed. The surface acquisition process is a two step one. Firstly, the surface normals are computed using a shape-from-shading algorithm. Secondly, the field of surface normals is integrated into a 3D surface. For the surface integration step, we have performed experiments wi...
متن کاملThe Lawn-Mowing Algorithm for Noisy Gradient Vector Fields
In this paper we analyze a specific problem within the context of recovering the geometric shape of an unknown surface from multiple noisy shading patterns generated by consecutive parallel illuminations by different light-sources. Shading-based single-view shape recovery in computer vision often leads to vector fields (i.e. estimated surface normals) which have to be integrated for calculation...
متن کاملVector Transport for Shape-from-Shading
In this paper we describe a new shape-from-shading method. We show how the parallel transport of surface normals can be used to impose curvature consistency and also to iteratively update surface normal directions so as to improve the brightness error. We commence by showing how to make local estimates of the Hessian matrix from surface normal information. With the local Hessian matrix to hand,...
متن کامل